Thursday 13 October 2016

A Brønsted Acid–Primary Amine as a Synergistic Catalyst for Stereoselective Asymmetric Diels–Alder Reactions








September 14 
 on facebook wrote, quote

I am happy to share with you our laboratory recent publication on asymmetric catalysis.

This communication deals with the understanding and development of Brønsted Acid-Primary Amine as a Synergistic-catalyst for Stereoselective Asymmetric Barbas [4+2]-cycloaddition reaction by using 2-aminobuta-1,3-diene-catalysis under ambient conditions.

I believe this reaction can become good tool for chemists.

I congratulate my co-workers for their hard work to make this work more successful.

For more information, please click below link:
http://onlinelibrary.wiley.com/doi/10.1002/ejoc.201601011/full          ..........unquote



(1R,3S,5S)-5-hydroxy-3-methyl-2'-oxospiro[cyclohexane-1,3'-indoline]-2,2-dicarbonitrile (7ag): Prepared by following the procedure E and purified by column chromatography using EtOAc/hexane and isolated as solid.

[]D 25 = –119.2 (c = 0.1 g/100 mL, CHCl3, 99% ee);

IR (Neat): max 3313, 2977, 2930, 1701, 1618, 1479, 1350, 1272, 1246, 1200, 1148, 1066, 1014 and 750 cm-1 ; 

1H NMR (CDCl3)  8.58 (1H, br s, NH), 7.64 (1H, d, J = 8.0 Hz), 7.41 (1H, t, J = 7.5 Hz), 7.23 (1H, t, J = 7.5 Hz), 6.99 (1H, d, J = 7.5 Hz), 5.32 (1H, dd, J = 11.0, 4.0 Hz), 4.22-4.18 (1H, m), 3.44-3.89 (1H, m), 2.33 (1H, dd, J = 16.0, 4.0 Hz), 2.20-2.13 (2H, m), 1.89 (1H, dt, J = 13.0, 3.5 Hz), 1.40 (3H, d, J = 6.5 Hz); 

13C NMR S-15 (CDCl3, DEPT-135)  178.2 (C, N_C=O), 139.8 (C), 130.9 (CH), 127.6 (C), 124.9 (CH), 124.2 (CH), 112.9 (C, CN), 111.8 (C, CN), 110.8 (CH), 64.7 (CH), 52.3 (C), 47.2 (C), 36.9 (CH2), 34.0 (CH2), 28.8 (CH), 18.4 (CH3); 

HRMS m/z 304.1060 (M + Na), calcd for C16H15N3O2Na 304.1062.











Ramachary D B

   








Dr. D. B. Ramchary, Ph.D. Associate Professor 
   School of Chemistry
   University of Hyderabad
   Prof. C. R. Rao Road, Gachibowli
   Hyderabad, 500046, India
   Tel: 0091-40-23134816
   Email: ramsc@uohyd.ernet.in

Ramachary obtained his Masters degree (General Chemistry) at the University of Hyderabad in 1996. There as part of curricula he studied and actively involved in the project, entitled Synthesis and Utilization of Aromatic Radical Anions for Reduction of Carbon Monoxide (with Prof. M. Periasamy).

Ramachary obtained his Doctoral degree (Organic Synthesis) at the Indian Institute of Science, Bangalore for his research work on Total Synthesis of Sesquiterpenes Containing Three Contiguous Quaternary Carbon Atoms (with Prof. A. Srikrishna).

In January 2002, he moved to Prof. Carlos F. Barabas III research group as Skaggs Post Doctoral fellow at The Scripps Research Institute, San Diego. After three year post doctoral studies at TSRI, he then joined as Faculty member in School of Chemistry, University of Hyderabad in Jan 2005, where at present he is a Reader.

Dr Ramachary has been awarded the INSA Medal for Young Scientists in Chemical Sciences for the year 2006 for his outstanding contributions to the emerging area of asymmetric organocatalysis.

The main focus of his research group is to engineer the novel and green asymmetric cascade and multi-component reactions (MCRs) to generate the biologically important molecules and natural products in a single step via emerging chiral amines or amino acid-catalysis.

His research group is actively engaged in the design and synthesis of novel enzyme mimetic small organic amines and amino acids to catalyze the fundamental organic reactions in enantioselective manner.

His interest about inquisitive questions like how small can be highly active and stereo-selective catalysts and what are the minimal functional and structural features required in a chiral catalyst had made him to venture in the most advanced versions of synthetic chemistry. 
For the more information about his research group please Click here for Home Page
Significant Publications:
D. B. Ramachary, M. Kishor and Y. Vijayendar Reddy, Development of Pharmaceutical Drugs, Drug Intermediates and Ingredients by Using Direct Organo-Click Reactions, Eur. J. Org. Chem., 2007, xxxx-xxxx (DOI: 10.1002/ejoc.200701014).

D. B. Ramachary, G. Babul Reddy and Rumpa Mondal, New Organocatalyst for Friedel-Crafts Alkylation of 2-Naphthols with Isatins: Application of an Organo-Click Strategy for the Cascade Synthesis of Highly Functionalized Molecules, Tetrahedron Lett., 2007, 48, 7618-7623.

D. B. Ramachary and M. Kishor, Organocatalytic Sequential One-Pot Double Cascade Asymmetric Synthesis of Wieland-Miescher Ketone Analogs from a Knoevenagel/Hydrogenation/Robinson Annulation Sequence: Scope and Applications of Organocatalytic Bio-Mimetic Reductions, J. Org. Chem., 2007, 72, 5056-5068.

D. B. Ramachary, K. Ramakumar and V. V. Narayana, Organocatalytic Cascade Reactions Based on Push-Pull Dienamine Platform: Synthesis of Highly Substituted Anilines, J. Org. Chem., 2007, 72, 1458-1463.

D. B. Ramachary and G. Babul Reddy, Towards Organo-Click Reactions: Development of Pharmaceutical Ingredients by Using Direct Organocatalytic Bio-Mimetic Reductions, Org. Biomol. Chem., 2006, 4, 4463-4468.

D. B. Ramachary and Rumpa Mondal, Direct Organocatalytic Hydroalkoxylation of a,b-Unsaturated Ketones, Tetrahedron Lett., 2006, 47, 7689-7693.

Jorly Joseph, D. B. Ramachary, Eluvathingal D. Jemmis, Electrostatic Repulsion as an additional Selectivity Factor in Asymmetric Proline Catalysis, Org. Biomol. Chem., 2006, 4, 2685-2689.

D. B. Ramachary, M. Kishor and G. Babul Reddy, Development of Drug Intermediates by Using Direct Organocatalytic Multi-Component Reactions, Org. Biomol. Chem., 2006, 4, 1641-1646.

D. B. Ramachary, M. Kishor and K. Ramakumar, A Novel and Green Protocol for Two-Carbon Homologation: A Direct Amino Acid/K2CO3-Catalyzed Four-Component Reaction of Aldehydes, Active Methylenes, Hantzsch Esters and Alkyl Halides, Tetrahedron Lett., 2006, 47, 651-656.

D. B. Ramachary, K. Ramakumar and M. Kishor, Direct Organocatalytic in situ Generation of Novel Push-Pull Dienamines: Application in Tandem Claisen-Schmidt/Iso-Aromatization Reactions, Tetrahedron Lett., 2005, 46, 7037-7042.

D. B. Ramachary and Carlos F. Barbas III, Direct Amino Acid-Catalyzed Asymmetric Desymmetrization of meso-Compounds: Tandem Aminoxylation/O-N Bond Heterolysis Reactions, Org. Lett., 2005, 7, 1577-1580.

D. B. Ramachary, Naidu S. Chowdari and Carlos F. Barbas III, Organocatalytic Asymmetric Domino Knoevenagel/Diels-Alder Reactions: A Bioorganic Approach to the Diastereospecific and Enantioselective Construction of Highly Substituted Spiro[5,5]undecane-1,5,9-triones, Angew. Chem. Int. Ed., 2003, 42, 4233-4237. 

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Wednesday 12 October 2016

From Box to Bench: Air-Stable Molybdenum Catalyst Tablets for Everyday Use in Olefin Metathesis

Abstract Image

Molybdenum- and tungsten-based olefin metathesis catalysts have demonstrated excellent results in the control of cis (Z-) selectivity as well as enantioselectivity. However, their air and moisture sensitivity, which requires the use of a glovebox, has prevented their more widespread use by organic chemists. Now we report on developed, preweighed Mo catalysts formulated in paraffin tablets. 

The significantly improved air stability, high homogeneity, and uniformity of the pellets allow researchers to carry out reactions on the bench avoiding the need of a glovebox.

The two different Mo-based complexes which were packed into tablets are XiMoPac-Mo001 (1) that can be used to achieve endo-selective enyne ring-closing metathesis (RCM) reactions, interalia; and XiMoPac-Mo003 (2) which was reported among the best catalysts to promote Z-selective cross-metathesis. 

For the evaluation of the wax-protected catalysts commonly used, highly reproducible robust model reactions were chosen: homo cross-metathesis (HCM) of functionalized (e.g., methyl 9-decenoate) and unfunctionalized (allylbenzene) terminal olefins, and ring closing metathesis (RCM) of diethyl diallylmalonate. The yields and conversions were comparable with those which can be achieved in glovebox with nonformulated catalysts. 

Exposure to air did not cause any significant reduction in conversion while the product selectivity (targeted product vs homologues derived from double bond isomerization) remained high. In contrast, exposure to air caused a measurable drop in the conversion with the nonprotected catalyst. Furthermore, the formulated catalysts remained unaffected even after 4 h of exposure to air, showing its enhanced air stability. 

In conclusion, these commercially available air-stable Mo-catalyst tablets allow the reactions to be accomplished using ordinary Schlenk techniques, and hence simplify catalyst handling in pilot laboratories and plants.

From Box to Bench: Air-Stable Molybdenum Catalyst Tablets for Everyday Use in Olefin Metathesis

 XiMo Hungary Ltd., 7. Zahony Str., Budapest HU-1031, Hungary
 XiMo AG, 3. Altsagenstrasse, Horw/Luzern CH-6048, Switzerland
Org. Process Res. Dev., Article ASAP
DOI: 10.1021/acs.oprd.6b00161

*Telephone: (36) 1 580 2202; Fax: (36) 1-580 2201; E-mail: levente.ondi@ximo-inc.com.
http://pubs.acs.org/doi/abs/10.1021/acs.oprd.6b00161


Levente Ondi


Levente Ondi

Director of R. & D. at XiMo Hungary Ltd.


https://hu.linkedin.com/in/levente-ondi-2005931a

Experience

Director of R&D

XiMo Hungary Ltd.
 – Present (3 years 11 months)

Head of Chemistry Lab.

XiMo Hungary Ltd.
 –  (2 years 1 month)

Head of R&D Laboratory II.

Chemical Future Pharma Ltd.
 –  (2 years 7 months)

Research Scientist

Chemical Future Pharma Ltd.
 –  (2 years 6 months)

Education







Map of Ximo Hungary Kft.
Ximo Hungary Kft. 
Chemical Plant
AddressBudapest, ZĂ¡hony utca 7. D Ă©pĂ¼let, 1031 Hungary

Ximo - Members of the Board






Prof. Dr. Georg FrĂ¡ter
Chief Operating Officer
 
  • Over 30 years experience in the Swiss chemical industry
  • Over 20 years in the fragrance and flavor industry, five as Research Director for Givaudan
  • Former President Swiss Chemical Society (SCS)
  • Former Professor at the University of ZĂ¼rich
  • Current member of the board of Thales Nano
 
Education: Ph.D. University of Zurich; M.Sc. University of Zurich

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Wednesday 5 October 2016

A Rapid microwave assisted synthesis of novel 1,4-dihydropyridines derivatives under aqueous medium



Chemistry & Biology Interface

July-August 2012, Volume 2, No.4

July-August 2012, Volume 2, No.4
Chemistry & Biology Interface, 2012, 2, 4, 206-257
(ISSN: 2249 – 4820)


A Rapid microwave assisted synthesis of novel 1,4-dihydropyridines derivatives under aqueous medium
Shailesh Thakrar, Dhairya Bhavsar, Vicky Jain, Anamik Shah 

Chemistry & Biology Interface, 2012, 2, 4, 220-227 pg 220-227, Department of Chemistry, Saurashtra University, Rajkot-360005, India
 
[Full Text-PDF]

Keywords: 1, 4-dihydro pyridines, Pyrazole aldehyde, One-pot, Microwave, Aqueous medium,
Fe+3 montmorillonite clay K-10, HY-zeolite.
Abstract: An environment friendly synthesis of 1,4-dihydropyridine derivatives was developed by one pot multi component reaction of pyrazole aldehyde, EAA/MAA, 3-amino crotononitrile and Fe+3 montmorillonite clay K-10/ HY-zeolite under microwave irradiation in aqueous medium. The structures of all synthesized compounds were well characterized by Mass, FT-IR, 1H NMR and elemental analysis.

Methyl 5-cyano-1,4-dihydro-2,6-dimethyl- 4-(1,3-diphenyl-1H-pyrazol-4-yl)pyridine- 3-carboxylate (5a): MP: 182-184 oC; IR (cm-1): 3489, 3367, 3198, 2974, 2897, 2332, 2260, 1707, 1660, 1587, 1519, 1435, 1356, 1282, 744, 688. MS: m/z = 426.17; 1H NMR (DMSO-d6) δ ppm: 2.14(s, 6H), 2.58(s, 3H), 4.91(s, 1H), 6.91-6.99(d, 2H), 7.20-7.22(t, 2H), 7.29-7.31(t, 1H), 7.45-7.49(t, 2H), 7.60-7.62(d, 1H), 7.71-7.73(d, 2H), 7.95(s, 1H), 8.74(s, 1H). MS: m/z: 410.17; Anal. Calcd. for C25H22N4O2: C, 73.15; H, 5.40; N,13.65; O,7.80; Found: C, 73.06; H, 5.36; N, 13.61; O,7.79(%).





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Lewis acid-catalyzed 2-arylquinazoline formation from N′-arylbenzimidamides and paraformaldehyde

Graphical abstract: Lewis acid-catalyzed 2-arylquinazoline formation from N′-arylbenzimidamides and paraformaldehyde




2-phenylquinazoline (2a, CAS: 25855-20-3)[2]

1 H NMR (400 MHz, CDCl3, ppm) δ 9.48 (s, 1H), 8.63-8.60 (m, 2H), 8.11-8.09 (m, 1H), 7.95-7.89 (m, 2H), 7.64-7.60 (m, 1H), 7.57-7.49 (m, 3H);

13C NMR (100 MHz, CDCl3, ppm) δ 161.1, 160.5, 150.8, 138.0, 134.1, 130.6, 128.6, 128.6, 128.6, 127.2, 127.1, 123.6 ;

MS (EI) ) m/z (%) 206, 197, 179, 105 (100), 77.

Wang, H. M.; Chen, H.; Chen, Y.; Deng, G. J. Org. Biomol. Chem. 2014, 12, 7792

2-phenylquinazoline








Lewis acid-catalyzed 2-arylquinazoline formation from N[prime or minute]-arylbenzimidamides and paraformaldehyde

Green Chem., 2016, Advance Article
DOI: 10.1039/C6GC02319C, Communication
Xiufang Cheng, Huamin Wang, Fuhong Xiao, Guo-Jun Deng
An efficient procedure for the synthesis of 2-arylquinazolines from N[prime or minute]-arylbenzimidamides has been developed under transition-metal-free conditions.

An efficient procedure for the synthesis of 2-arylquinazolines from N′-arylbenzimidamides has been developed under transition-metal-free conditions. In this process, stable and low-toxicity paraformaldehyde was used as the carbon source. A broad range of functional groups were well tolerated in this reaction system.

Lewis acid-catalyzed 2-arylquinazoline formation from N′-arylbenzimidamides and paraformaldehyde

Xiufang Cheng,a   Huamin Wang,a   Fuhong Xiao*a and  Guo-Jun Deng*a  
*
Corresponding authors
a
Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, China
E-mail: gjdeng@xtu.edu.cnfhxiao@xtu.edu.cn
Fax: (+86)0731-5829-2251
Tel: (+86)0731-5829-8280
Green Chem., 2016, Advance Article

DOI: 10.1039/C6GC02319Chttp://pubs.rsc.org/en/Content/ArticleLanding/2016/GC/C6GC02319C?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract





























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